Cutter chain and cutter bar



N. D. LEVIN CUTTER CHAIN AND CUTTER BAR Jan. 26, 1937.

Filed March 21, 1936 o f/VVENTOR: NILS D. LEVIN,

BY QZ/VVK. 7% 71M, I

ATTX

Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE Nils D. Levin,Columbus, Ohio, assignor to The .lefirey Manufacturing Company, acorporation of Ohio Application March 21, 1936, Serial No. 70,035

14 Claims.

This invention relates to a cutter bar and cutter chain for a miningmachine.

An object of the invention is to provide an improved type of stiff-backcutter chain adapted to cooperate with a cutter bar having wear strips;said. cutter bar being constructed to prevent its clamping the wearstrips during operation and tearing them from the cutter bar.

Another object of the invention is to provide an improved cutter chainof the stiff-back type with means to prevent tilting of the forwardportion of the bit carrying links thereof.

Still another object of the invention is to pro vide an improved type ofbit carrying link for a cutter chain.

Other objects of the invention wil appear hereinafter, the novelfeatures and combinations being set forth in the appended claims.

In the accompanying drawing,

Fig. 1 is an elevational View of a section of a cutter chain comprisingmy invention;

Fig. 2 is a transverse sectional view of the cutter bar and cutter chaincomprising my invention;

Fig. 3 is an elevational View of a bit carrying link of a cutter chaincomprising my invention; Fig. 4 is a rear end view of the link of Fig.3;

Fig. 5 is an elevational view of one strap of the connecting link of thecutter chain; and

Fig. 6 is an end view of the strap of Fig. 5.

This invention comprises an improvement on the cutter chain and cutterbar, as well as on the bit carrying link, disclosed in my application,Serial No. 729,522 filed June '7, 1934, for a Cutter chain and cutterbar.

The invention herein disclosed is designed to overcome certainundesirable characteristics which have been found to be possessed by theinvention of the above mentioned application, which will be set forth indetail hereinafter.

Referring particularly to Figs. 1 and 2 of the drawing, there is seen acutter bar I!) formed by top and bottom plates ll between which ispositioned a central plate 92, said plates II and I2 being rigidlyattached together as by rivets l3. Adjacent the outer ends of the topand bottom plates l l are L-shaped wear strips M which have outerbearing surfaces 55 along which shoulders of the cutter chain, ashereinafter described, are adapted to ride and having inner bearingledges l6 adapted to retain the cutter chain on the cutter bar. It willbe seen that the plates II and I2 along with the Wear strips I4 providea longitudinally extending recess l7 adapted to receive a cutter chainH3. The cutter chain i8 is formed by alternate interconnected bitcarrying links l9, and connecting links 26.

The bit carrying links l9 are formed by a central Web or body portion 2|provided with a pair of spaced apertures 22, one at each end. Ex- 5tending upwardly from the web- 2| and above the rear aperture 22 is abit carrying lug 23 having a screw threaded aperture 24 adapted toreceive a screw 25 which clamps a pair of clamp plates 26 and 2? betweenwhich is clamped a cut- 10 ter bit 28. The lug 23 is provided with ashoulder or fiat transverse seat 29 which cooperates with clamp plate2'! to determine the inclination of the bit 28. The bit 28 may be astar-shaped bit whereby a plurality of working faces. are pro- 15 videdwhich may be successively brought into operative position. In accordancewith well known practice, adjacent bits 28 on the cutter chain will beinclined at different angles and preferably formed as a spiralprogressively along H the cutter chain, thereby to cut a kerf which hasa width slightly greater than the thickness of the cutter bar.

The lug 23 also provides a pair of laterally extending shoulders 36having bottom bearing surfaces 3l, said surfaces 31 being adapted toride upon the outer bearing surfaces I5 of the Wear strips l4. Extendingforwardly from the web 2i there is an abutment 32 having a bottombearing surface 33 and an arcuate top or upper bearing surface 34.Adjacent the rear end of the bit carrying link 19 there is provided anabutment 35 having a horizontal bottom bearing surface 36 and an arcuatebottom or lower bearing surface 31. The functions of these bearingsurfaces 33, 34, 36 and 3'! will be described in detail hereinafter.

Inter-connecting adjacent bit carrying links I?) are the connectinglinks 20 formed by a pair of side straps 38, each of which has aninwardly projecting integral lug 39 at each end thereof adapted to bereceived by an aperture 22 of a bit carrying link. The lugs 39 areprovided with apertures 40 adapted to receive a rivet 4| to form acomplete connecting link 20 and attach it for pivotal movement withrespect to a bit carrying link l9. Also adjacent the top and midwaybetween the lugs 39 each of said side straps 38 is provided with aninwardly extending abutment lug 42.

In the assembled cutter chain the bottom bearing surfaces 33 and 36 ofthe bit carrying links [9 are adapted to overlap and ride on theinwardly extending abutment lugs 42 of the connecting links 20. Thisconstruction would alone provide a stiff-back type of chain. It has beenfound, however, if no further provision is made for a stiff-back type ofchain of the general con struction herein disclosed, that when inoperation there is a tendency for the bit carrying link 59 to tilt abouta fulcrum formed by the rear portions 43 of the laterally extendingshoulders 30, which ride upon the bearing surfaces I5 of the wear stripsi4. As a consequence of this tilting about the rear portions 43 as afulcrum, the forward portion 44 of the connecting links 28 will belifted to make contact with the inner bearing ledges if; of the wearstrips I l. It is thus evident that the wear strips it will be clampedbetween the portions 43 of the shoulders 39, and the portions 44 of theconnecting links 20. This clamping or gripping action will be generallyafter the fashion of a clutch and will cause a very serious frictionalrubbing between the clamping surfaces and may even result in the tearingof the wear strips M from the cutter bar to which they are normally heldas by rivets 45. In order, therefore, to prolong the life of the wearingstrips M as well as the life of the cut ter chain and to avoid thetearing loose of the wearing strips i l, I provide the cooperatingoverlapping abutments 34 and 35 on adjacent bit carrying links !9. Asclearly seen in Fig. l of the drawing, the abutment 32 has a top orupper bearing surface 34 adapted to be contacted by the bottom or lowerbearing surface 31 on abutment 35 of the preceding bit carrying link. Asa consequence, it would be impossible for any bit carrying link to tiltabout the fulcrum formed by rear portions 4-3 of shoulders 30, thus theabove mentioned clutching or clamping action is avoided. This is, ofcourse, due to the fact that any tendency for the forward portion of abit carrying link to pivot or tilt about the rear portions 43 of theshoulders 39 is effectively resisted by a downward force applied theretoby the preceding bit carrying link by virtue of the overlapping relationof the rear abutment 35 of a preceding bit carrying link with theforward abutment 32 of a following bit carrying link, the forces beingtransmitted through the bearing surfaces 3 5 and 31. As a consequence, Ihave provided a stiff-back type of chain which is entirely free toarticulate in one direction, but which is prevented from articulating inan opposite direction; that is, the chain may freely form a concavecurve, but not a convex curve.

Furthermore, the tilting of any individual bit carrying link, which, incooperation with a connecting link might effect a clamping or grabbingaction on a wear strip, is effectively eliminated.

It is also to be noted that the tilting action of any bit carrying linkl9 about the portions 43 as a fulcrum is effectively resisted not onlyby all subsequent links which is characteristic of the stiff-back typeof chain, but any tilting is also resisted by a preceding bit carryinglink due to the contacting between abutments 32 and 35 along bearingsurfaces 34 and 31.

Furthermore, should the bearing surfaces 31 become worn to allow thebottoms of links 19 and 2D to ride on plate 12 then the thrust on anybit carrying link i9 would be distributed over the bottom bearing areaof all adjacent bit carrying links i9 and connecting links 28, by virtueof the abutment between bearing surfaces 33 and 36 and abutments 42.This would equalize, and thereby reduce, the wear on the bottoms of alllinks of the chain, both bit carrying and connecting links.

It is also to be noted that the outer surfaces of the side straps 38forming the connecting links 25 have a large bearing area to slide alongthe interior surfaces of plates H adjacent recess ll, thereby to preventexcess wear on said links or cutter bar 353 due to any tendency for thechain to rotate or twist about a longitudinal axis thereof under theinfluence of bit 28. This influence is accentrated by those bits whichextend at wide angles to the plane of the cutter bar It] to cut the topand bottom portions of the kerf above and below the central portionthereof. This twisting may also be resisted by contact between a bearingsurface 35 on shoulder 30 and a bearing surface 15 on one wear strip !4,and by contact between the top of one side strap 38 and an inner bearingledge IS on the other wear strip i l.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts Without departing from the spirit andscope of the invention as defined by the claims hereto appended, and Itherefore wish not to be restricted to the precise construction hereindisclosed.

Having thus described and shown an embodiment of my invention, what Idesire to secure by Letters Patent of the United States is:

l. A cutter chain comprising bit carrying links and connecting links,means for connecting said links, contacting abutment means carried bythe two types of links providing a stiff-back chain,

adjacent bit carrying links having overlapping normally contactingabutments.

2. A cutter chain comprising bit carrying links, means connecting saidlinks, and overlapping normally contacting abutment means on adjacentbit carrying links.

3. A cutter chain comprising bit carrying links and connecting links,means connecting said links, contacting abutment means carried by saidtwo types of links, and overlapping normally contacting abutment meanson adjacent bit carrying links both of which contact said connectinglink abutment means.

l. A cutter chain comprising bit carrying links and connecting links,means connecting said links, bits on said bit carrying links having acutting edge requiring the chain to move in one direction, and abutmentmeans on adjacent bit carrying links so constructed and arranged thatthe abutment on the forward end of a trailing bit carrying link isoverlapped and normally contacted by an abutment on the rear end of aleading bit carrying link, both of said abutments abutting saidconnecting link.

5. A cutter chain comprising bit carrying links, means connecting saidlinks, bits on said bit carrying links having a cutting edge requiringthe chain to move in one direction, and abutment means on adjacent bitcarrying links so constructed and arranged that the abutment on theforward end of a trailing bit carrying link is overlapped and normallyengaged by an abutment on the rear end of a leading bit carrying link.

6. A cutter chain comprising interconnected bit carrying links andconnecting links, abutment means on two bit carrying links contactingabutment means on an intermediate connecting link providing a stifi-backchain, said abutment means on said bit carrying links being inoverlapping and normally engaging relation, with that on the foremost ontop.

'7. A cutter chain comprising interconnected bit carrying links andconnecting links, abutment means on two bit carrying links contactingabutment means on an intermediate connecting link providing a stiff-backchain, said abutment means on said bit carrying links being inoverlapping and normally engaging relation.

8. A cutter chain comprising interconnected bit carrying links andconnecting links, said bit carrying links having a central webpositioned between spaced side straps of said connecting links, inwardlyextending abutment means carried by the side straps of said connectinglinks, outwardly extending shoulders on said bit carrying linksoverhanging said connecting links, and overlapping normally engagingabutment means on said bit carrying links at least one of which abutsthe abutments on said connecting links thereby providing a stiff-backchain.

9. A cutter chain comprising interconnected bit carrying links andconnecting links, said bit carrying links having a central webpositioned between spaced side straps of said connecting links, inwardlyextending abutment means carried by the side straps of said connectinglinks, and overlapping normally engaging abutment means on said bitcarrying links at least one of which abuts the abutments on saidconnecting links thereby providing a stiff-back chain.

10. A cutter chain comprising interconnectedbit carrying links andconnecting links, said bit carrying links having a central webpositioned between spaced side straps of said connecting links, inwardlyextending abutment means carried by the side straps of said connectinglinks, outwardly extending shoulders on said bit carrying links, andoverlapping normally engaging abutment means on said bit carrying linksat least one of which abuts the abutments on said connecting linksthereby providing a stifi-back chain.

11. A bit carrying link for a mining machine cutter chain comprising acentral web, a bit carrying lug extending therefrom, cutter bar engagingshoulders on said lug, and abutments extending forward and rearwardly ofsaid web, said forward abutment having a top bearing surface and saidrearward abutment having a bottom bearing surface.

12. A bit carrying link for a mining machine cutter chain comprising acentral body, a bit carrying lug extending therefrom, cutter barengaging shoulders on said body, and abutments extending forward andrearwardly of said body, said forward abutment having a top bearingsurface and said rearward abutment having a. bottom bearing surface.

13. A bit carrying link for a mining machine comprising a body, anabutment extending forwardly therefrom, an abutment extending rearwardlytherefrom, said forward abutment having an upper bearing surface andsaid rear abutment having a lower bearing surface.

14. A bit carrying link for a mining machine comprising a body, anabutment extending forwardly therefrom, an abutment extending rearwardlytherefrom, one of said abutments having an upwardly exposed bearingsurface and the other a downwardly exposed bearing surface.

NILS D. LEVIN.

